Parameters, characteristics, working principle and application of HL201A GTR driver

HL201A is a special thick film driver integrated circuit with a capacity of less than 75AGTR developed by Xi'an Power Electronics Technology Research Institute. The article explains the pin arrangement, usage and function of HL201A. It also explains the main parameters and characteristics of the device, analyzes its working principle and internal structure, and gives its typical application circuit and actual circuit used in chopper system.

HL201A GTR driver is suitable for direct drive of less than 75A GTR. It is manufactured by thick film process and has built-in differential transformer, which can realize the isolation of input and output signals. It has the advantages of high reliability, small degree of influence by environmental factors, relatively low price and excellent performance. HL201A GTR thick film driver is the first of its kind in my country. It has fast response speed and Baker clamp terminal, which can be realized by connecting with high reverse voltage fast diode MUR1100. Its large output power can directly drive GTR mode within 75A.

1. Pinout and Function

HL201A is packaged in a standard 16-pin thick film integrated circuit package in accordance with the Single In-Line Package Act. Its pin arrangement is shown in Figure 1. The symbol, name, function and instructions for use of each pin are listed in Table 1.

Table 1 HL201 pin description

2. Features and parameters

HL201A has a wide adaptability to power supplies, large output drive current, and a wide operating frequency. The circuit uses thick film packaging, which improves its adaptability to the environment.

The main electrical parameters of HL201A are as follows:

Power supply voltage: Vcc = +8 ~ 10V, VEE = -5 ~ -7V;

The maximum output current is greater than ±25A at the leading edge, the leading edge rise time is <1μs, and it is 1.5A at the flat top;

Output drive signal: high level > 5V, current absorption < 5mA;

Input and output response time < 1.5μs;

The isolation voltage between input and output is 2500V/minute at power frequency.

3. Internal structure and working principle

The user can control the pulse of the loop to drive the isolation differential transformer after the VT1 power amplifier, and then the pulse amplification and shaping circuit will shape and amplify it before output. When the output pulse is high level, the pulse is limited by the resistor R2 to turn on the transistor VT2, so as to drive the power GTR to saturate and turn on. At this time, the oversaturated drive current will be shunted through the Baker clamp diode connected to pin 15. When the output pulse is low level, VT2 is turned off, and the PNP power transistor VT3 is turned on to quickly extract the residual carriers of the driven GTR base-emitter junction, so that the driven GTR is quickly turned off.

4. Application

1) Typical application circuit

The positive drive current output by HL201A is:

IB1=（Vcc-Vce（set/（Rc+RB1）））

For a 50A Darlington GTR component, IB1 should be around 0.5A. For a 75A GTR component, IB1 needs to be around 1A, and RB1 is generally 1Ω. Then:

RC=[(Vcc-Vce（sat)）/IB1]-1 （Ω）

This formula is explained as: Vcc is the supply voltage, Vce (sat) is the saturation voltage drop of the driven GTR, usually the resistance Rc is 5~10Ω, the inductance LB is generally a few μH, and RB2>Rc is generally taken in use.

2) Practical application circuit

Regarding the chopper switching power supply made by using HL201A to drive GTR, the power GTR used is a 50A three-stage Darlington type, and the input signal is generated by TI's (Texas Instruments, referred to as TI, is a leading global semiconductor company that provides innovative digital signal processing (DSP) and analog technology for real-world signal processing.) PWM generator TL494.